/*
** Nofrendo (c) 1998-2000 Matthew Conte (matt@conte.com)
**
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of version 2 of the GNU Library General
** Public License as published by the Free Software Foundation.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
** Library General Public License for more details.  To obtain a
** copy of the GNU Library General Public License, write to the Free
** Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
**
** Any permitted reproduction of these routines, in whole or in part,
** must bear this legend.
**
**
** map64.c
**
** mapper 64 interface
** $Id: map064.c,v 1.2 2001/04/27 14:37:11 neil Exp $
*/

#include <noftypes.h>
#include <nes_mmc.h>
#include <nes.h>
#include <log.h>

static struct
{
    int counter, latch;
    bool enabled, reset;
} irq;

static uint8 command = 0;
static uint16 vrombase = 0x0000;

static void map64_hblank(int vblank)
{
    if (vblank)
        return;

    irq.reset = false;

    if (ppu_enabled())
    {
        if (0 == irq.counter--)
        {
            irq.counter = irq.latch;

            if (true == irq.enabled)
                nes_irq();

            irq.reset = true;
        }
    }
}

/* mapper 64: Tengen RAMBO-1 */
static void map64_write(uint32 address, uint8 value)
{
    switch (address & 0xE001)
    {
    case 0x8000:
        command = value;
        vrombase = (value & 0x80) ? 0x1000 : 0x0000;
        break;

    case 0x8001:
        switch (command & 0xF)
        {
        case 0:
            mmc_bankvrom(1, 0x0000 ^ vrombase, value);
            mmc_bankvrom(1, 0x0400 ^ vrombase, value);
            break;

        case 1:
            mmc_bankvrom(1, 0x0800 ^ vrombase, value);
            mmc_bankvrom(1, 0x0C00 ^ vrombase, value);
            break;

        case 2:
            mmc_bankvrom(1, 0x1000 ^ vrombase, value);
            break;

        case 3:
            mmc_bankvrom(1, 0x1400 ^ vrombase, value);
            break;

        case 4:
            mmc_bankvrom(1, 0x1800 ^ vrombase, value);
            break;

        case 5:
            mmc_bankvrom(1, 0x1C00 ^ vrombase, value);
            break;

        case 6:
            mmc_bankrom(8, (command & 0x40) ? 0xA000 : 0x8000, value);
            break;

        case 7:
            mmc_bankrom(8, (command & 0x40) ? 0xC000 : 0xA000, value);
            break;

        case 8:
            mmc_bankvrom(1, 0x0400, value);
            break;

        case 9:
            mmc_bankvrom(1, 0x0C00, value);
            break;

        case 15:
            mmc_bankrom(8, (command & 0x40) ? 0x8000 : 0xC000, value);
            break;

        default:
#ifdef NOFRENDO_DEBUG
            log_printf("mapper 64: unknown command #%d", command & 0xF);
#endif
            break;
        }
        break;

    case 0xA000:
        if (value & 1)
            ppu_mirror(0, 0, 1, 1);
        else
            ppu_mirror(0, 1, 0, 1);
        break;

    case 0xC000:
        // irq.counter = value;
        irq.latch = value;
        break;

    case 0xC001:
        // irq.latch = value;
        irq.reset = true;
        break;

    case 0xE000:
        // irq.counter = irq.latch;
        irq.enabled = false;
        break;

    case 0xE001:
        irq.enabled = true;
        break;

    default:
#ifdef NOFRENDO_DEBUG
        log_printf("mapper 64: Wrote $%02X to $%04X", value, address);
#endif
        break;
    }

    if (true == irq.reset)
        irq.counter = irq.latch;
}

static void map64_init(void)
{
    mmc_bankrom(8, 0x8000, MMC_LASTBANK);
    mmc_bankrom(8, 0xA000, MMC_LASTBANK);
    mmc_bankrom(8, 0xC000, MMC_LASTBANK);
    mmc_bankrom(8, 0xE000, MMC_LASTBANK);

    irq.counter = irq.latch = 0;
    irq.reset = irq.enabled = false;
}

static map_memwrite map64_memwrite[] = {{0x8000, 0xFFFF, map64_write}, {-1, -1, NULL}};

mapintf_t map64_intf = {
    64,               /* mapper number */
    "Tengen RAMBO-1", /* mapper name */
    map64_init,       /* init routine */
    NULL,             /* vblank callback */
    map64_hblank,     /* hblank callback */
    NULL,             /* get state (snss) */
    NULL,             /* set state (snss) */
    NULL,             /* memory read structure */
    map64_memwrite,   /* memory write structure */
    NULL              /* external sound device */
};

/*
** $Log: map064.c,v $
** Revision 1.2  2001/04/27 14:37:11  neil
** wheeee
**
** Revision 1.1  2001/04/27 12:54:40  neil
** blah
**
** Revision 1.1.1.1  2001/04/27 07:03:54  neil
** initial
**
** Revision 1.1  2000/10/24 12:19:33  matt
** changed directory structure
**
** Revision 1.8  2000/10/22 19:17:46  matt
** mapper cleanups galore
**
** Revision 1.7  2000/10/22 15:03:13  matt
** simplified mirroring
**
** Revision 1.6  2000/10/21 19:33:38  matt
** many more cleanups
**
** Revision 1.5  2000/10/10 13:58:17  matt
** stroustrup squeezing his way in the door
**
** Revision 1.4  2000/07/10 13:51:25  matt
** using generic nes_irq() routine now
**
** Revision 1.3  2000/07/10 05:29:03  matt
** cleaned up some mirroring issues
**
** Revision 1.2  2000/07/06 02:48:43  matt
** clearly labelled structure members
**
** Revision 1.1  2000/07/05 05:05:18  matt
** initial revision
**
*/
